Section 319
NONPOINT SOURCE PROGRAM SUCCESS STORY
Implementing Various Pollution Control and Restoration Practices
Improves Water Quality in Noxontown Pond
Waterbody Improved
Stormwater runoff from agricultural and urban areas contributed
nonpoint source pollutants to Delaware's Noxontown Pond,
prompting Delaware's Department of Natural Resources and Environmental Control (DNREC)
to add the pond to the 1998 Clean Water Act (CWA) section 303(d) list for bacteria and
nutrients. Watershed stakeholders provided technical assistance, installed agricultural best
management practices (BMPs), implemented low impact development designs and restored
streambanks. Bacteria levels declined, and DNREC removed the Noxontown Pond segment of
the Appoquinimink watershed from the state's 2006 list of impaired waters for bacteria.
Problem
Noxontown Pond covers approximately 158 acres
near the headwaters of the 47-square-mile
Appoquinimink River watershed, adjacent to the
town of Townsend. The headwaters drain mostly
agricultural lands and feed four major ponds, includ-
ing Noxontown Pond. The 16-mile Appoquinimink
River meanders through farmlands and wetlands in
southern New Castle County and eventually flows
into the Delaware Bay (Figure 1). It also contains
three of the fastest growing towns in the state:
Odessa, Townsend and Middletown.
Much of the watershed is actively cultivated;
however, as development occurs south of the
Chesapeake and Delaware Canal, farmland is being
converted into suburban residential developments.
Today, less than 9 percent of the watershed remains
forested. Between 1992 and 2007, watershed
impervious cover increased from 4 to 9 percent; it
is projected to reach a maximum of 25 percent in
the future.
Monitoring data collected in the late-1990s indicat-
ed that Noxontown Pond failed to meet the state's
enterococcus bacteria numeric criterion, which
requires that the annual geometric mean be less
than 100 colony-forming units (CPU) per 100 mil-
liliters (ml). The pond did not support its freshwater
primary contact designated use, prompting the
state in 1998 to add the pond to Delaware's CWA
section 303(d) list of impaired waters for bacteria.
The pond was also listed as impaired for nutrients
in 1998.
£3 Chesapeake Watershed
£3 Delaware Watershed
Figure 1. Noxontown Pond is one of four
major ponds in the watershed that flow into
Appoquinimink River in northern Delaware.
In 2003 the U.S. Environmental Protection Agency
developed a total maximum daily load (TMDL) to
address the nutrients and dissolved oxygen impair-
ments throughout the Appoquinimink watershed,
which includes Noxontown Pond. The TMDL
requires a 60 percent reduction in nitrogen and
phosphorus. In 2006 DNREC also developed a bac-
teria TMDL for the Appoquinimink watershed, which
required an 11-15 percent reduction in the nonpoint
source bacteria load in freshwater areas.
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Project Highlights
The New Castle County Conservation District
(NCCD) offered technical assistance to the farming
community by providing nutrient management plan-
ning and cost-share funding for agricultural BMPs.
NCCD also partnered with the U.S. Department of
Agriculture (USDA) Natural Resources Conservation
Service (NRCS) to develop conservation plans and
Environmental Quality Incentive Program (EQIP)
contracts. Between 2000 and 2012, watershed part-
ners worked with landowners to restore approxi-
mately 10 acres of wetlands, establish almost
4 acres of riparian buffers, plant 250 acres of cover
crop, enroll 800 acres in conservation crop rotation,
install 1,354 acres of irrigation water management
and implement nutrient management plans on
2,326 acres.
In 2000, DNREC created an Appoquinimink
Tributary Action Team to develop recommenda-
tions for meeting the TMDL goals. In 2004, as
recommended by the Action Team, the nonprofit
Appoquinimink River Association (ARA) was formed
to help watershed partners implement water quality
protection projects. Since then, ARA has provided
important environmental education and outreach
throughout the region. With help from ARA,
Middletown passed an Environmental Protection
Ordinance in 2007 to establish Riparian Buffer Area
Conservation Districts to regulate uses, activities
and development in areas adjacent to waterbodies
in the Appoquinimink River watershed.
Delaware's USDA Conservation Reserve
Enhancement Program (CREP) was established in
1999 to protect and enhance environmentally sensi-
tive land and waters in the coastal plain geographic
areas of the Delaware, Chesapeake and Inland Bays
watersheds by establishing voluntary land retire-
ment agreements with agricultural producers. To
assist in CREP program development and implemen-
tation, in 1999 Delaware's Nonpoint Source Program
committed CWA section 319 funds to create a
full-time Delaware CREP Program Coordinator posi-
tion. Between 1999 and 2012, the CREP Program
Coordinator used the Delaware CREP to help install
19.4 acres of wildlife plantings, 54 acres of grass
buffers, and numerous other conservation practices
throughout the Appoquinimink River watershed.
Results
Enterococcus Bacteria Annual Geometric Mean (2002-2012)
Figure 2. The annual geometric mean of enterococcus bacteria
data for 2002-2012 show that Noxontown Pond meets the
state's numeric bacteria criterion, which requires an annual
geometric mean of less than 100 CFU/100 ml.
watershed that have helped to reduce bacteria
in surface waters. Water quality monitoring data
collected from Noxontown Pond (station 109131)
in 2002-2012 showed that the enterococcus
bacteria annual geometric means comply with the
numeric criterion necessary to support the pond's
freshwater primary contact recreation designated
use (Figure 2). On the basis of these data, DNREC
removed Noxontown Pond from the state's 2006
list of impaired waters for bacteria. Data show that
Noxontown Pond water quality continues to meet
the bacteria water quality standard. The pond
remains listed as impaired for nutrients.
Partners and Funding
For more than 10 years, watershed partners
have implemented water quality protection and
restoration efforts in the Appoquinimink River
Key partners were the NCCD, USDA NRCS, ARA
and the Delaware Nonpoint Source Program.
Approximately $118,400 in federal CWA section
319 funds supported the costs of the Noxontown
Pond projects. Additional funding was provided
through the USDA EQIP and CREP, and Delaware's
Conservation Cost Share program (which was
provided through the NCCD). Because of the nature
of the funding and enrollment procedures, much
of the funding provided by watershed partners has
been immeasurable.
UJ
O
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-13-001L
April 2013
For additional information contact:
Bob Palmer
Delaware DNREC
Nonpoint Source Program
robert.palmer@state.de.us • 302-739-9922
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